Spamdexing (a buzz word that is a combination of both spamming and indexing) is a term that means search engine spamming. Spamdexing or search engine spamming refers to the practice of intentionally creating web pages which will be indexed by search engines in order to increase the chance of a website or page being placed close to the beginning of search engine results. Some spamdexing is conducted to try and influence the category to which the page is assigned. Many designers of web pages try to get a good ranking in search engines and design their pages accordingly.
Search engines use a variety of algorithms to determine the ranking and relevancy of a web page. Some of these include determining whether the search term appears in the META keywords tag, others whether the search term appears in the body text or URL of a web page. A variety of techniques are used to commit the SEO crime of spamdex including content spamming and link spamming. Many search engines check for instances of spamdexing and will remove suspect pages from their indexes. Some search engines will also ban a site for spamdexing.
Spamdexing has done the Internet a lot of damage; in particular to the way we search for information. The rise of spamdexing in the mid-1990s made the leading search engines of the time less useful. One of the reasons that Google is so successful is that its founders invented a PageRank link system that defied spamdexing and made Internet searches more relevant to the links that would actually show up on search engine pages.
Google is not invulnerable to spamdexing or other more sophisticated methods of search engine spamming (also known as black hat SEO.) Google bombing is another form of search engine result manipulation, which involves placing hyperlinks that directly affect the rank of other sites on a page to try and boost rankings.